Each of these two concurrent meetings, one focusing on Cell Compartmentalization and one focusing on Antigen Processing & Development, will attract an audience of scientists who identify with the major topics of each conference. Questions to be answered in these fields in the coming years include how proteins become integrated into membrane systems, how these organelles maintain their structural & functional integrity, and identifying the components responsible for the sorting steps, organellar movement & fusion reactions that accompany protein transit. Recent cloning of genes encoded into the MHC region, which effects peptide transport, protein breakdown, etc., gives clues on how the immune system evolved. Questions which remain are how proteins are digested to generate antigenic peptides, how peptides are selected, how they are bound to MHC molecules, etc. The organizers of these two meetings, while addressing issues of importance to their own constituency, hope to bring together major contributors in these fields. It is hoped that the opportunity to interact outside the formal program sessions, the presence of planned joint sessions which will 'formally' bring together both groups of scientists will encourage the formation of new collaborative relationships which will bear fruit in the not too distant future as well as the immediate transfer of knowledge and technique and an appreciation for the achievements and challenges associated with these two related fields of scientific endeavor.